Method of and means for forming pipe elbows



Sept. 7 1926. 1,598,893

J. H. TAYLOR METHOD OF AND MEANS FOR FORMING PIPE ELBOWS Filed Oct. 31,1921 2 Sheets-Sheet 1 Patented Sept. 7 1926.

JAMES HALL TAYLOR, OF CHICAGO, ILLINOIS. v

I ETHOIQOF AND MEANS IQR FORMING PIPE ELBOWB.

Application filed October :1, 1921. Serial No. 511,800.

The present invention pertains to a method of and means for forming pipeelbows. The invention proposes making pipe elbows out of sections ofsubstantially straight tubing by drawing these sections over internaland external forming members with which cooperate internal and externalpivoted dies.

This particular method will be described in detail in the followingdescription taken in connection with the accompanying drawings in whichFigure 1 illustrates the manner of cutting the straight stock tubing ondiagonal planes so as to eliminate waste;

Fig. 2 illustrates the section of tubing, in position between theformingmembers and dies, the latter being illustrated diagrammatically;ig. 2 is an end elevational view of theforming members and dies, theinternal horn and die being illustrated in section;

Fig. 3 shows the outer and inner dies revolved downwardlv, illustratingthe first tratin curve completed;

Fig. 4'llustrates the next step in one manner of performing the processwith the pipe section reversed to dispose the straight end over the hornand outer forming member;

Fig. 5 is a view similar to Fig. 3 illusthe final step of rounding thisstraig t end; and 3 Fig. 6-is an elevational view on a smaller scale ofthe completed elbow.

The stock wrought metal tubing "designated 10 is cut'intonnit lengths onalternately inclined diagonal planes so as to leave the diagonal ends11. Each section of tubing 10' is then inserted horizontally into theforming machine. The machine comprises inner and'outer forming membersconsisting of an inner horn 14 which extends into the end of. the pipesection ape; an outer form 15 which engages with the' exterior of thepipe section at its bottom. These two form'- ing members extend upwardlyfrom a suitable support, not; shown) The horn 14 has pivotal orotherlsuitable movable connection 'with its support in order that it maybe quickly and easily inserted into the end of the pipe section. Thecurving of the pipe section ,is performed upon the upper sur faces 14'and 15' of these two forming members, these surfaces'as viewed from theside being curved substantially concentrically about a common center :0.As viewed in the transverse plane represented in Fig. 2, both of theseforming members are curved to conform to their respective portions ofthe completed elbow. That is to say, the forming surface of the outerforming member 15 is concave'and of semi-circular outline to embrace andshape the inner portion of the elbow. The horn 14, on the other hand, isconvex and of semi-circular contour to shape the outer half of theelbow.. The lateral walls 16 of the outer forming member 15 terminatesubstantially co-incidentwith the under surface 17 of the horn, thisunder surface 1 corresponding substantially with .the horizontaldiametrical plane passing through the center of-the pipe elbow.

Cooperating with the two forming members 14 and 15 are the two swingingdies 18 and 19. The die 18 extends into the interior of the. pipesection and is formed with a convex die face 18' to agree with theconcave curvature'of the forming member 15. The outer die member 19 isadapted to form the exterior portion of the elbow and its die face 19'is given a concave curvature to correspond with the convex curvature ofthe horn 14. The two die members are arranged to'follow the circularcontours of their respective forming members, either through pivotalconnections, by following curved guiding means, or in any other suitablemanner. In Figure 2 I have shown the outer die 19 as being mountedbetween parallel arms 20 which have pivotal connection with the machineon pivots 21 aligned on the pivotal center at. The inner die 18 has anextending arm 21 adapted to reach outside of the pipe section 10 formaking connection with asuitable supporting member or frame adapted todraw the die over the form 15. The lower surface 17 of the horn 14 isconcentric with the lower forming surface 15 and is intended to functionas a bearing surface against which the top of the die 18 bears and isguided. This bearing contact insures the requisite pressure for drawingdown the inner portion of the elbow. The two points of bearing contactbetween the die 18 and horn 14 may be arranged for adjustment or renewalby the provision of shims or the like.

The pipe section 10' is first inserted wlth the dies in the positionshown in Fig. 2, the long edge of the diagonal end 11 being i l:-permost for shaping over .the horn 14. e pipe section is onl insertedhalfway to dispose the center 0 the section substantially may at theforward edge of the horn 14. Any suitable clamping apparatus may besecured to the projecting end of the pipe section for holding it inplace. The two dies are then 6 swung downwardly around the circularcontours of their respective forming members as shown in Fig. 3. Thelongitudinal curving of the pipe section is the result. The dotted linepositions of the two dies are for the purpose of representing theforming action which takes place. The action of the outer die 19 .is tocompress or shrink the metal transversely and lengthen it longitudinallyin drawing it over the born 14. The action of the inner die is tostretch the metal in drawing it downwardly over the outer forming member15. Owing to the fact that the curving ofthe tube is performed bydrawing both the inner and outer circumferences, there is no bunching ofthe curvin metal in the inner circumference, nor any thickening of theinner wall so often char acteristic of other methods. The downwarddrawing of the metal in the operation of the inner wall of the blanktends to slightly reduce the sectional thickness of this wall from thecentral plane outwardly towards the ends of the blank. Prior methods offorming pipe elbows of relatively small radii have in the main beendeficient or objectionable because of the buckling of the metal andother similar difiiculties, preventing the commercial production of thistype of elbow. My experience has proven 5 the present method to be theonly process which efl'ectively takes care of excess metal and obviatesthese difliculties. The diagonal end 11 of each pipe section ispreferably ,cut at such angle that the completion of the curvingoperation illustrated in Fig. 3 will leave the curved end of the pipesection substantially flush with a radial plane passing through thecenter a: of the elbow. This minimizes or eliminates waste of materialvwhich would otherwise be involved in trimmin or facing the end of theelbow.

T e pipe section is now withdrawn from the machine and the dies returnedto their upri ht positions, whereuponthe other end 0? t e pipe sectionis inserted between the dies and orming members, as showninFig.

. 4. The dies are then rotated for repeating the previdus drawingoperation on this end of t e pipe section. This latter step isillustrated m Fig. 5. According to this manner of performing1 theprocess the pipe sect1on 10 is in eac instance inserted in the machineto dispose its central transverse ,plane substantially coincident withthe end of the horn 14, whereby each operation of the dies 18 and 19'shapes one-half-of the elbow. Both ends of the pipe section may becurved simultaneously if desired. The performance of such double curvingoperation merely requires a duplication of the .from substantiallystraight tu forming and die members for the other end. The outer forminsurfaces 15' on plane. ranged for cooperation with the left handforming. surface 15. Similarly, a duplicate horn 14 would be insertedinto the left th sides of its central hand end of the pipe section and adupli cate die 19 would be arranged to cooperate with this horn. Thesimultaneous actuation of both sets of dies in opposite directions wouldsubstantially neutralize any stresses tending to move the pipe section.However,

comprises taking aseption of wrought steel- -tubing having an obliqueend, engaging the long side which defines an acute'angle with theoblique end over an internal horn, and the short side which defines anobtuse angle with the oblique end over an external form, moving an.external die down over .the long side of the oblique end to shr nk themetal over said internal horn, and moving an internal die in enga ementwith the short side of said oblique en .to stretch the metal over theexternal form.

member, 15 has forming A duplicate die 18 would be ar- 2; The method ofcurving tubing which comprises disposin said tubing over an internalhorn and a jacent an external form, said horn and form havingsubstantially concentric curvatures moving an internal die alon tubing1'. ereto, and movlng an external d 1e along said internal horn to shapethe tubing thereto.

3. The method of forming elbows which comprises disposing a section oftubmgover a curved internal horn and adjacent an external form, and thenmoving internal and external dies substantially parallel with the facesof said internal horn and said external form to shape the tubingthereto.

4. The. method of curvmg tubing wh ch comprises disposin said tubingover an mternal horn and said horn and form having concentrically curvedfaces, and then mo internal and external dies concentrically with saidcurved faces to shape the tubing thereto.

5. The method of producing ipe. elbows ing wh ch comprises cuttingsaidtu ing into sections on alternately inclined planes, disposing eachsection in association with a forming memberengag'ing exteriorly withsaid tubjacent an external form,.

said external form to shape the outer form for shaping the tubing o ingand a forming horn extending interiorly into said tubing, said forminfimember and said horn having concentrica y curved forming surfaces, andmoving co-foperating dies concentrically with said curved surfaces forshe ing the inner and outer portions of said tu ing thereto.

of said tubing down upon said external form, and mo an external diesubstantiall concentri only of said internal form to shrink: the m inthe-outer circumferential wall of said tubing down over said internalform.

- 7. In a tube shaping device, a statidnary 1 pro ect inside of curvedhorn adapted to the tubing a curved form outside of the tubing, and iemembers moving concentrically with the curved faces of said horn andthereto. 8. In a tube shaping device the class described, thecombination of an outer form vmg a concave forming surface curvedlongitudinall of the section of tubing to be shaped there y, a hornadapted v into said section of tubing, said born a convex forming curvedlongitudinally of the tubing, an inner die rotatable within said sectionof tubing concentrically with the longitudinal curvature of said outerform, said Inner die having a convex die face co-operating withtheconcave surface of said outer form and an outer die rotatableconcentrically of the longitudinal curvature of said horn, said outerdie having a concave die face co-o' rating with the convex curvature ofsai horn.

9. In a forming machine for making pi elbows, an internal horn ofsubstantia y semi-circular convex section adapted for insertion into oneend of the pipe, an external form of substantially semi-circular concavei section adapted for a with the exterior of said pipe, an external diefor drawing the outer circumference of the elbow over the internal horn,and an internal die for drawing the inner circumference of the elbowover the external form.

10. In a tube shaping devi a horn adapted for insertion into the tu ing,said horn being of semi-circular contour on its outer surface, means forshaping one portion of the tubing over said horn, a 0 and a die co-operatherewith said die ing movable within e tubin for shap' another portionthereof, sai die havmg rcooperation with said horn.

witness whereof, I hereunto 1 sub- JAMES HALL TAYLOR.

my name this 28th day of October,

